Air expansion nozzle for high pressure ventilation

ABSTRACT

An air introduction nozzle for high pressure-ventilated spaces has a substantially low-cylindrical structure and a centrally located air inlet space with a cylinder shell, which is provided with openings and is radially cylindrically surrounded by at least two air expansion spaces, filled with an air-permeable material. The air expansion spaces are separated from one another by cylinder shells provided with openings. The air is discharged from the nozzle through openings of the outermost cylinder shell enclosing the at least two air expansion spaces.

BACKGROUND OF THE INVENTION

The invention relates to the ventilation and simultaneous air conditioning of buildings.

Ventilation in low-energy buildings, in other words buildings with low energy consumption. does not generally take place by means of windows. but by means of ventilation ducts.

The use of compressed air for the mechanical ventilation and air conditioning of buildings makes substantial space gains possible compared to conventional solutions by means of ventilation ducts.

It is already known to retrospectively provide buildings with compressed air lines, with the aid of which the space ventilation can be carried out. The possibility for air conditioning spaces is simultaneously provided here on the basis of the Joule-Thomson effect during the air expansion.

A problem not hitherto adequately solved was, however, the noise disturbance from the expansion process at the nozzles.

SUMMARY OF THE INVENTION

The object of the invention is to provide an air introduction nozzle for high pressure-ventilated spaces, which no longer adversely affects people when working or sleeping. The nozzle should, for this purpose, be in a position to reduce compressed air from a pressure range between 2 and 12 bar to ambient pressure (approximately 1 bar) and, in this case, to only generate less than 40 dB(A), preferably less than 37 dB(A) of noise, It should also have a low space requirement and not be visually intrusively conspicuous.

The object is achieved as follows. The air introduction nozzle for high pressure-ventilated inhabited spaces, which expands air from a pressure range of 2 to 12 bar to ambient pressure and, in this case, has low sound emissions of less than 40 dB(A), is characterized in that

-   -   the nozzle has a substantially low-cylindrical structure with a         ratio of height to diameter of the cylinder of less than 1:3,     -   the nozzle has a centrally located air inlet space LE (9) with a         cylinder shell ZE (10), which is provided with openings and is         radially cylindrically surrounded by at least two air expansion         spaces L1 (6), L2 (7), . . . filled with an air-permeable         material,     -   the air expansion spaces L1 (6), L2 (7), . . . are separated         from one another by cylinder shells Z1 (4) provided with         openings, and     -   the air discharges through the outermost cylinder shell (5) into         the space to be ventilated.

The air introduction nozzle is further characterized in that the cylinder shell ZE (10) of the air inlet space LE (9) has openings OPE with a diameter of 0.2 to 2 millimetres.

The air introduction nozzle is further characterized in that the ratio of the sum of the opening areas of the openings OPE in the cylinder shell ZE (10) to the total lateral surface of ZE (10) is less than 0.05.

The air introduction nozzle is further characterized in that the openings OP1 in the external shell Z1 (4) of the first air expansion space L1 (6) are greater than the openings OPE in the cylinder shell ZE (10) of the air inlet space LE (9)

The air introduction nozzle is further characterized in that the ratio of the sum of the opening areas of the openings OP1 in the cylinder shell Z1 (4) to the total lateral surface of the cylinder shell Z1 (4) is at least 0.02.

The air introduction nozzle is further characterized in that the openings OP2 in the external shell Z2 (5) of the second air expansion space L2 (7) are greater than the openings OPE in the cylinder shell ZE (10) of the air inlet space LE (9).

The air introduction nozzle is further characterized in that the ratio of the sum of the opening areas of the openings OP2 in the cylinder shell Z2 (5) to the total lateral surface of the cylinder shell Z2 (5) is at least 0.05.

The air introduction nozzle is further characterized in that the radial spacing dl of the cylinder shell surface ZE (10) from the cylinder shell surface Z1 (4) is greater than the radial spacing d2 of the surface of the cylinder surface Z1 (4) from the surface of the cylinder shell Z2 (5).

The air introduction nozzle is further characterized in that the air-permeable material contained in the air expansion spaces L1 (6), L2 (7), is a band-shaped wound nonwoven NW.

The air introduction nozzle is further characterized in that the cylinder shell ZE (10) of the air inlet space LE (9) and the cylinder shells Z1 (4), Z2 (5), of the air expansion spaces L1 (6), L2 (7), . . . have the same height between the end plate (1) and the base plate (2) of the nozzle.

Accordingly, the invention provides that the air introduction nozzle is to be very flat so that it can be attached to a ceiling or wall inconspicuously. The ratio of the height to the diameter is less than 1:3, preferably less than 1:4.

The air introduction nozzle has a substantially low-cylindrical structure. The center forms a preferably cylindrical air inlet space LE. On one side (bottom face of the cylinder) the latter has the inlet opening for the compressed air and, on the other side (top side of the cylinder), the cylinder is closed.

Narrow openings (passages) OPE, for example simple bores, which radially guide the compressed air onward into a first air expansion space L1, are located at the periphery of the air inlet space LE (the cylinder shell ZE). This air expansion space L1 also surrounds the cylindrical air inlet space LE cylindrically and, in a preferred configuration, has the same height. Its external wall (intermediate cylinder shell Z1) is formed by a cylinder shell Z1, also provided with openings OP1. The cylinder shell Z1 has the same height as the cylinder wall ZE of the air introduction space LE.

The space in this first air expansion space L1 is filled with a gas-permeable material. In an advantageous configuration, this is a band (width preferably equal to the height of the air expansion space L1), which is wound around the cylinder shell ZE of the air inlet space LE and thereby fills up the air expansion space L1.

The first air expansion space L1 is furthermore surrounded by a second air expansion space L2. This air expansion space L2 is preferably also cylindrical, It, too, is surrounded by a cylinder shell Z2 (outermost cylinder shell) provided with openings OP2 and, in its interior, contains a gas-permeable material, which is advantageously, as already in L1, wound around the external cylinder shell Z1 of the air expansion space L1.

The following air expansion space L2 generally has the same height as the air expansion space L1. However, it is also possible to make the air expansion space L2 higher than L1. For this purpose, the external cylinder shell Z1 of air expansion space L1 is (preferably) elevated and the external cylinder shell Z2 of air expansion space L2 is also elevated to the same height. The interior L2 between the lateral cylinder surfaces of cylinder shells Z1 and Z2 is also filled with a gas-permeable material in this embodiment.

It has, however, been shown that an air expansion space L2 of the same height as air expansion space L1 is sufficient to achieve sufficient noise damping during the air expansion process. It has surprisingly been found that it is not possible to dispense with the external shell Z1 around the air expansion space L1, in other words to only use a single unified air expansion space L1+L2 with a greater diameter for compressed air expansion. No satisfactory results for noise damping could be achieved for a unified air expansion space.

According to the invention, it is also possible to use additional air expansion spaces L3, . . . filled with air-permeable material with external cylinder shells Z3, but two air expansion spaces L1 and L2 have proven to be adequately noise-damping for human hearing.

Apart from the type of gas-permeable material, the size and the number of openings also has an influence on the noise damping action.

The cylinder shell ZE of the air introduction space has openings OPE with a small diameter, the total opening area of which is small in comparison to the cylinder surface of the cylinder shell ZE. The ratio of the combined opening areas to the “active” total cylinder surface area (this only means the cylinder surface area pointing toward the air expansion space L1) is less than 0.05, preferably less than 0.02.

The diameter of the opening is (for the case of circular bores) 0.2 to 2 millimetres, preferably about 1 mm.

The gas-permeable windable material is preferably a band-shaped nonwoven NW.

A material with a thickness of 4 mm and a mass per unit area of 600 Wm has proven to be suitable, The thickness may vary approximately by up to the factor of 3 and the mass per unit area by up to the factor of 2.

A nonwoven made with needled polyester staple fibers has proven to be particularly suitable, A suitable nonwoven of this type with the type name HDF H2511 may be acquired from the company FILL (31-1234 Menge{hacek over (s)}).

The nonwoven is wound with low tension around the respective inner cylinder shell so that its thickness is only slightly reduced (less than 30%).

The external cylinder shell Z1 of the first air expansion space L1 also has openings OP1, which are greater, however, than in the inner cylinder shell ZE. Moreover, the ratio of combined opening areas of the openings OP1 to the total cylinder area of the external cylinder shell Z1 is preferably greater than in the case of the inner cylinder surface of the air inlet space LE, namely at least 0.02.

The openings OP2 in the external cylinder shell Z2 of the air expansion space L2 also preferably have greater diameters than the diameters of the openings OPE provided on the innermost cylinder shell ZE. The ratio of the combined opening areas of the openings OP2 to the total cylinder area of the external cylinder shell Z2 is likewise preferably greater than that of the innermost cylinder surface of the cylinder shell ZE of air inlet space LE, namely at least 0.05, preferably at least 0.1.

In order to achieve good sound damping, it is also preferred that the radial spacing d1 of the cylinder surfaces of cylinder shell ZE relative to cylinder shell Z1 and radial spacing d2 of cylinder shell Z1 relative to cylinder shell 12 is not of the same size; it is preferred that d1 is greater than d2.

The spacing d1 is preferably approximately 20% to 100% greater than d2. It has proven to be very suitable to select d1 to be greater than d2 by 50%.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures describe, without restricting the generality of the invention, an embodiment for ceiling ventilation by means of high pressure ventilation at 10 bar. In the figures, the ventilation nozzle is shown upside down compared to its mounted position hanging from the ceiling. A nozzle of this type could, however, also be fastened vertically to the wall, behind a heating body or behind or in a cabinet.

FIG. 1 shows a perspective total view of a cutaway ventilation nozzle.

FIG. 2 shows a cross-section through the ventilation nozzle of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a perspective total view of a cutaway ventilation nozzle. The actual gas expansion part according to the invention is also provided with a visually pleasing panel or covering 8 shaped like a turned-over plate, which is connected by connecting means 12 to the gas expansion part. The panel 8, however, also contributes additionally, even though to a small extent, to the noise damping action in that it blocks noise coming from the air introduction space LE 9.

The cylinder top face and base face are configured here as an end plate 1 and base plate 2, which are held together by screws 11 (also by connecting means 12), as an excess pressure, which would drive the plates apart, prevails between the two plates 1 and 2.

The compressed air feed line in the form of a connecting piece leads through the base plate 2 into the air introduction space LE 9. In the embodiment, the cylinder wall ZE 10 extends downward beyond the base plate 2 and forms the connecting piece to the high pressure pipe.

The air introduction space LE 9 in this embodiment, apart from the end plate 1, is expediently closed upwardly toward the end plate 1 by cylinder end plate 10 a.

The total part consisting of the perforated cylinder shell ZE 10, cylinder end plate 10 a, and feed line is designated an expansion core 3 in the figure.

The external diameter of the outermost cylinder wall Z2 (5) is 190 mm. The internal height of the nozzle cylinder (spacing between the end plate 1 and base plate 2) is 30 mm. The air introduction space LE (9) has an internal diameter of 30 mm in the embodiment. However, depending on the application and total size of the air introduction nozzle, this may vary within a broad range. Sensible diameters are between 10 and 100 millimetres,

The described embodiment allows an air throughput of 90 m³/h at a discharge speed of the air from the nozzle of 21 to 3 m/s. The development of noise is very low here at 35 to 37 dB(A).

The specification incorporates by reference the entire disclosure of European priority document 11 179 993.8 having a filing date of 05 Sep. 2011.

While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

LIST OF REFERENCE NUMERALS

-   1 end plate -   2 base plate -   3 expansion core -   4 cylinder shell Z1 with openings OP1 -   5 cylinder shell Z2 with openings OP2 -   6 air expansion space L1 with air-permeable material e.g. nonwoven     NW) -   7 air expansion space L2 with air-permeable material (e.g. nonwoven     NW) -   8 visually pleasing panel covering -   9 air inlet space LE -   10 cylinder shell ZE with openings OPE -   10 a cylinder end plate -   11 connection (for example screw) between 1 and 2 -   12 connection (for example screw) between 1, 2 and 8 -   d1 radial distance between ZE and Z1 -   d2 radial distance between Z1 and Z2 

1. An air introduction nozzle for high pressure-ventilated inhabited spaces, which expands air from a pressure range of 2 to 12 bar to ambient pressure and has low sound emissions of less than 40 dB(A), the nozzle having a substantially low-cylindrical structure defined by a ratio of height to diameter of the low-cylindrical structure of less than 1:3; the nozzle comprising: an air inlet space with a cylinder shell that is located centrally relative to the substantially low-cylindrical structure of the nozzle; the cylinder shell of the air inlet space provided with openings; at least two air expansion spaces filled with an air-permeable material; wherein the at least two air expansion spaces surround in radial direction cylindrically the air inlet space; wherein the at least two air expansion spaces are separated from one another by an intermediate cylinder shell provided with openings; and an outermost cylinder shell enclosing the at least two air expansion spaces, wherein air is discharged from the nozzle through openings of the outermost cylinder shell.
 2. The air introduction nozzle according to claim 1, wherein the openings of the cylinder shell of the air inlet space have a diameter of 0.2 to 2 millimetres,
 3. The air introduction nozzle according to claim 1, wherein a ratio of the sum of the opening areas of the openings of the cylinder shell of the air inlet space to a total lateral surface of the cylinder shell of the air inlet space is less than 0.05.
 4. The air introduction nozzle according to claim 1, wherein the openings in the intermediate cylinder shell are greater than the openings in the cylinder shell of the air inlet space.
 5. The air introduction nozzle according to claim 4, wherein a ratio of the sum of the opening areas of the openings of the intermediate cylinder shell to the total lateral surface of the intermediate cylinder shell is at least 0.02.
 6. The air introduction nozzle according to claim 1, wherein the openings in the outermost cylinder shell are greater than the openings in the cylinder shell of the air inlet space.
 7. The air introduction nozzle according to claim 1, wherein a ratio of the sum of the opening areas of the openings of the outermost cylinder shell to the total lateral surface of the outermost cylinder shell is at least 0.05.
 8. The air introduction nozzle according to claim 1, wherein a radial spacing of the cylinder shell of the air inlet space relative to the intermediate cylinder shell is greater than a radial spacing of the intermediate cylinder shell relative to the outermost cylinder surface.
 9. The air introduction nozzle according to claim 1, wherein the air-permeable material is a band-shaped wound nonwoven.
 10. The air introduction nozzle according to claim 1, comprising an end plate and a base plate, wherein the cylinder shell of the air inlet space, the intermediate cylinder shell and the outermost cylinder shell have the same height measured between the end plate and the base plate. 